On: “RECENT TECHNIQUES FOR DETERMINATION OF IN SITU ELASTIC PROPERTIES AND MEASUREMENT OF MOTION AMPLIFICATION IN LAYERED MEDIA,” BY R.J. SWAIN (GEOPHYSICS, APRIL, 1962, PP. 237–241).

Geophysics ◽  
1963 ◽  
Vol 28 (1) ◽  
pp. 112-112 ◽  
Author(s):  
Harry R. Nicholls
Keyword(s):  
Elastic Properties ◽  
Elastic Constants ◽  
Design Problem ◽  
Critical Angle ◽  
Specific Design ◽  
Design Problems ◽  
Relative Value ◽  
Angle Method

Although I am in general agreement with Mr. Swain’s paper, there are several pitfalls inherent in the use of dynamic elastic constants which should not be ignored. The strength of materials and the elastic properties both undoubtedly depend on the rate of loading and/or the stress levels involved. It does not seem appropriate, therefore, to use dynamic in situ elastic properties for static design problems. The specific design problem at hand should determine the relative value placed on the use of static or dynamic elastic constants. The dynamic in situ values are generally more reliable than those obtained in the laboratory as indicated by Mr. Swain, although continued development of the laboratory pulse and critical‐angle method shows promise of improving the reliability of laboratory values.

RECENT TECHNIQUES FOR DETERMINATION OF “IN‐SITU” ELASTIC PROPERTIES AND MEASUREMENT OF MOTION AMPLIFICATION IN LAYERED MEDIA

Geophysics ◽  
1962 ◽  
Vol 27 (2) ◽  
pp. 237-241 ◽  
Author(s):  
R. J. Swain
Keyword(s):  
Engineering Design ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Layered Media ◽  
Dynamic Loads ◽  
Safety Factors

Determination of the elastic properties of earth materials by laboratory means is subject to sizable errors. These errors may be serious in spite of the large safety factors normally used in engineering design, particularly if the structure must withstand severe dynamic loads. Means of obtaining elastic constants “in‐situ” are described. Further, the phenomenon of displacement multiplication between the underlying competent rock and overlying alluvium or fill is reviewed and the first instrumentation system designed specifically to measure this relationship for engineering purposes is described.

Design Option Decision Tree: A Method for Schematic Analysis of a Design Problem and Integration of Human Factors Data

1974 ◽  
Vol 18 (3) ◽  
pp. 368-375
Author(s):  
William B. Askren ◽  
Kenneth D. Korkan
Keyword(s):  
Decision Tree ◽  
Human Factors ◽  
Design Problem ◽  
Aircraft Design ◽  
Decision Point ◽  
Specific Design ◽  
Design Problems ◽  
Design Option ◽  
Design Options ◽  
Evaluation Parameters

A Design Option Decision Tree (DODT) is a graphic means of showing the design options available at each decision point in the design process. Several examples of DODTs for aircraft design problems are shown. The procedures for developing a DODT are described. A proposed method for use of the DODT to resolve a design problem is presented. This method includes evaluating the design options in the Tree for impact on the system, and tracing paths through the Tree as dictated by specific design goals. The use of human factors data as one of the evaluation parameters is illustrated. The paper concludes with a discussion of other uses of a DODT.

The Wolfrom Gear Train: A Case of Highest-Complexity Related Modifications of the Tooth Meshing

2009 ◽  
Author(s):  
Kiril Arnaudov ◽  
Dimitar Karaivanov
Keyword(s):  
Design Problem ◽  
High Speed ◽  
Technical Problem ◽  
Gear Train ◽  
Speed Ratio ◽  
Specific Design ◽  
Number Of Teeth

The Wolfrom gear is suitable for high speed ratios with an efficiency which is not optimal, but still acceptable. The version with single-rim satellites has significant design and technological advantages. However, the determination of the most appropriate modification coefficients poses a technical problem as the modifications are now related instead of being chosen independently. The geometrical calculations of the single-rim satellites version are performed in the paper. Speed ratio, number of teeth of the satellites, pressure angles and modification coefficients are determined. Advisable values for these parameters are given. As an example a specific design problem for the replacement of a three-stage planetary reducer (consisting of 15 gears) with a Wolfrom gear train (6 gears) the following calculations were performed.

Determination of in-situ elastic properties and reservoir boundary conditions

2020 ◽  
Vol 81 ◽  
pp. 103397
Author(s):  
Saeed Rafieepour ◽  
Silvio Baldino ◽  
Stefan Z. Miska
Keyword(s):  
Boundary Conditions ◽  
Elastic Properties

scholarly journals Determination of polycrystal diffraction elastic constants of Ti–2.5Cu by using in situ tensile loading and synchrotron radiation

2014 ◽  
Vol 594 ◽  
pp. 62-67 ◽  
Author(s):  
E. Maawad ◽  
H.-G. Brokmeier ◽  
Z.Y. Zhong ◽  
N. Al-Hamdany ◽  
M. Salih ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Elastic Constants ◽  
Tensile Loading

scholarly journals Determination of the high temperature elastic properties and diffraction elastic constants of Ni-base superalloys

2016 ◽  
Vol 89 ◽  
pp. 856-863 ◽  
Author(s):  
P.E. Aba-Perea ◽  
T. Pirling ◽  
P.J. Withers ◽  
J. Kelleher ◽  
S. Kabra ◽  
...  
Keyword(s):  
High Temperature ◽  
Elastic Properties ◽  
Elastic Constants

The Four-Box Method: Problem Formulation and Analogy Evaluation in Biologically Inspired Design

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Michael Helms ◽  
Ashok K. Goel
Keyword(s):  
Design Problem ◽  
Problem Formulation ◽  
Biologically Inspired ◽  
Design Problems ◽  
In Situ Observations ◽  
Box Method ◽  
Biologically Inspired Design ◽  
Search Design

Searching for biological analogies appropriate for design problems is a core process of biologically inspired design (BID). Through in situ observations of student BIDs, we discovered that student designers struggle with two issues that bookend the problem of search: design problem formulation, which generates the set of conditions to be used for search; and evaluation of the appropriateness of the retrieved analogies, which depends both on problem formulation and the retrieved analogy. We describe a method for problem formulation and analogy evaluation in BID that we call the Four-Box method. We show that the Four-Box method can be rapidly and accurately used by designers for both problem formulation and analogy evaluation, and that designers find the method valuable for the intended tasks.

Automated determination of n-cyanobiphenyl and n-cyanobiphenyl binary mixtures elastic constants in the nematic phase from molecular simulation

2020 ◽  
Vol 5 (6) ◽  
pp. 1131-1136
Author(s):  
Jiale Shi ◽  
Hythem Sidky ◽  
Jonathan K. Whitmer
Keyword(s):  
Liquid Crystals ◽  
Molecular Simulation ◽  
Elastic Properties ◽  
Binary Mixtures ◽  
Elastic Constants ◽  
Nematic Phase ◽  
New Techniques ◽  
New Applications ◽  
Automated Determination

This work explores new techniques in molecular simulation which can be used to precisely determine and engineer elastic properties of liquid crystals for new applications.

Determination of Elastic Constants for Human Femurs

1979 ◽  
Vol 101 (3) ◽  
pp. 193-197 ◽  
Author(s):  
V. G. Lappi ◽  
M. S. King ◽  
I. Le May
Keyword(s):  
Elastic Properties ◽  
Elastic Constants ◽  
Isotropic Material ◽  
Rotational Symmetry ◽  
Transversely Isotropic ◽  
Longitudinal Axis ◽  
Transversely Isotropic Material ◽  
Axis Of Symmetry ◽  
Plane Of Isotropy

The elastic properties of the bone constituting human femurs have been determined from measurements of the velocities of ultrasonic compressional and shear waves through wet, embalmed bone samples. The bone has been shown to be a transversely isotropic material with the axis of symmetry parallel to the longitudinal axis of the bone. The values of the elastic constants were determined to be: c11=6860±330MPaE3=5500MPac12=2700±570MPaE1=4990MPac13=3760±1570MPaν31=0.39c33=8480±760MPaν12=0.20c44=2240±180MPaG31=2240MPa where the 3-axis is that of rotational symmetry and the 1- and 2-axes are in the plane of isotropy.

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